A conventional driving tool that is disclosed in FIG. 7 and generally includes a driving head 10 which has a driving protrusion 11 extending from an end thereof so as to be engaged with a sleeve or a socket for example. A passage is defined through the head 10 and a bar 20 movably extends through the passage. The user holds the bar 20 and rotates the head so as to tighten or loosen an object such as a bolt head or a nut. Although the bar 20 can be moved through the passage to adjust the arm of force when applying a torque to the object. The bar 20 has a circular cross section and the passage is a round through hole, so that the bar 20 could be rotated when the user operates it. The user's hand could slip from the bar 20 and hit objects around the tool. Furthermore, after the user releases the bar 20, the bar 20 moves due to the gravity if the bar 20 is oriented an angle relative to the top of the table or the floor. The user has to re-arrange the bar 20 to a desired position again and this costs a lot of time.
FIG. 8 shows another cruciform driving tool which has two bars 20 fixedly connected at two respective intermediate points thereof and each bar 20 has a reception end for accommodate a bolt head or a nut therein. Unfortunately, the two bars 20 are fixed with each other and occupy a lot of space which is not convenient for storage. Although the two bars 20 can be made to be pivotably connected each other, the pivot area will be a weak spot which cannot bear a large torque.
The present invention intends to provide a driving tool that has a positioning member for preventing the bar from rotating in the passage of the driving head.